Electric meter.



No. 698,649. Patented Api'. 29, I902.

T. DUNCAN.

ELECTRlG METER- (Application filed July 10. 1899.] (No Model.) 2 Sheets-5heet l.

Witwwwo 3 vvuawboz $513 abrdz nm e Qt? dill Patented Apr. 29, I902. T. DUNCAN.

ELECTRIC METER. (App lication filed July 10, 1599.

(No Model.) 2 Sheets-Sheet 2.

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UNI ED STATES PATENT OFFICE.

I THOMAS DUNCAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THESIEMENS 85 HALSKE ELECTRIC COMPANY OF AMERICA, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

.ELECTVRIC METER."

SPECIFICATION forming part of Letters Patent No..698,649, dated Apri129, 1902.

Application filed July 10, l 899. Serial No. 723,328. (No model.)

To all whom it may concern:

out in the appended claims, and will be fully understood from the following-detailed description of the constructions illustrated in the accompanying drawings, in which-.

Figures 1, 2, 4E, and 5 are partially diagrammatic views of meters embodying my invention. Fig. 3 is a vector diagram of the essential current effects.

In said drawings, A designates a rotary armature that is actuated in a familiar manner by the inductive influence of series and volt coils B and C, of which the former is connected in series in the work-circuit WV and the latter in shunt across the line. An impedancecoil D is inserted in the shunt-circuit with the volt-coil to retard the current therein, and the armature is set in rotation by the resultant shifting field, due to this phase displacement. ever, necessary to obtain the full ninety-degree displacement necessary to accurate working under all conditions of service. In the present improvement such means consists of a secondary coil D, placed in inductive relation to the impedance-coil D and connected with the terminals 0 and c of the volt fieldcoil, so that the current induced therein by the shunt-current in the impedance-coil combines with the latter current in energizing said volt field-coil. This secondary current is displaced from the impressed electrometive force of the work-circuit by more than ninety degrees, and therefore in eifect increases the lag of the primary shunt-current pedance-coil D.

current in the coil D, andfthe slight current Additional lagging means are, howi through the impedance-coil, their resultant Be it known that I, THOMASWDUNCAN, of

action in the volt-coil being with'proper proportioning that of a single current lagging by l the ninety degrees desiredy This effect of the' secondary induced currentwill be somewhat diminished by the small shunt-current, which will traverse. the secondary coil D through the leads (Z, d, (P, and d in a direction opposite to said induced current; bu t the latter will still be great enough to accomplish the result required. H I

The essential current relations in the above respect are shown graphically in Fig. 3, in which the line E represents the electromotive force of the work circuit, and F the main shuntcurrent, which, as before stated, is displaced somewhat less than ninety degrees in phase from the electromotive force by the im- F represents the induced or leakage, which is deflected through the coil D in opposition to saidinduced current.

These two currents maybe said toproduce a resultant F (obtained by completing the parallelogram on lines F and f,) as the efiective current through said coil D, and this resultant,combined with the primary shunt-current F, (obtained by completing the parallelogram on lines F and F gives a final resultant F at ninety degrees with the electromotive force E as the effective current through the volt fieldcoil 0, which produces the magnetic field acting on the armature Ato represent the difference inpotential between the main leads of the work-circuit.

An adjusting device for exactly regulating the phase'retardation' is shown in Figs. 1, 2, and 4. as provided in theform of a closed-circuit coil D which is wound on the same magnetic core D as the coils D and D and has an inserted adjustable resistance D. In Figs. 1 and 2 an additional adjusting means is provided in the formof an adjustable resistance D connected in series with the coil D, and

in the latter figure a still further adjustment provement and are mentioned merely for the purpose of enabling the complete installation to be fully understood.

I claim as my invention-- 1. An electric meter provided with an armature, series and volt coils inductively actuating the armature, an impedance-coil connected in the shunt-circuit with the volt-coil, and

a secondarycoil placed in inductive relation to the impedance-coil and having its terminals connected with the terminals of the Voltcoil, the said secondary coil being directly connected in multiple with the winding in circuit with the impedance-coil, substantially as described.

2. An electric meter provided with an armatii're, series and volt coils for inductivelyactuating the armature, an impedance-coil connected in the shunt-circuit with the volt-coil, a secondary coil placed in inductive relation to the impedance-coil and having its terminals connected with the terminals of the voltcoil, and a closed-circuit adjusting-coil placed in inductive relation to the impedance and secondary coils.

3. An electric meterprovided with an armature, series and volt coils inductively actuating the armature, an impedance-coil connected in a shunt-circuit with a volt-coil, a secondary coil placed in inductive relation to the impedance-coil, and having its terminals con nected with the terminals of the volt-coil, the secondary coil being connected directly in multiple with the volt-coil in circuit with the impedance-coil, substantially as described.

4. The combination with the work-circuit,

of an electric meter provided with an armature A, an energizing-coil B connected in series in said work-circuit, an energizing-coil C connected in shunt across the line, an impedance-coil D inserted in said shunt-circuit, a secondary coil D placed in inductive relation to the impedance-coil D having its terminals connected with the terminals of the coil 0, the secondary coil being directly connected in multiple with the energizing-coil in circuit with the impedance-coil, a measuring device R and a magnetic drag S, substantially as described.

5. An electric meter provided with an armature, two windings for efiecting the operation of the armature, an impedance-coil connected in series with one of the windings, and a secondary coil placed in inductive relation to the impedance coil and directly connected in multiple with the field-winding in series with the impedance coil, substantially as described.

6. An electrical meter provided with an armature, series and volt windings for eifecting the operation of the armature, an impedancecoil connected in series with the volt-winding and a secondary coil placed in inductive relation to the impedance-coil and having its terminals connected with the terminals of the volt-winding, the secondary coil being directly connected in multiple with the Winding in series with the impedance-coil, substantially as described.

In testimony that I claim the foregoing as my invention I affix my signature, in presence of two subscribing witnesses, this 6th day of July, A. D. 1899.

THOMAS D UN CAN.

Vitnesses:

WVALTER II. ABBOTT, DAVID F. STAKES. 

